Apparatus for making yarns of artificial polymeric material



NOV. 11, 1969 LLlAMs 3,477,219 APPARATUS MAK YA OF ARTIFICIAL POLYMERICMA IAL Filed May 7, 1968 Inventor A llorncy United States Patent3,477,219 APPARATUS FOR MAKING YARNS 0F ARTIFICIAL POLYMERIC MATERIALRoy Alan Williams, Pontypool, England, assignor to Imperial ChemicalIndustries, Limited, London, England, a corporation of Great BritainFiled May 7, 1968, Ser. No. 727,284 Claims priority, application GreatBritain, May 10, 1967, 21,671/ 67 Int. Cl. D01h 7/02, 13/26; D07b 3/02US. Cl. 57-59 6 Claims ABSTRACT OF THE DISCLOSURE This applicationrelates to the manufacture of yarns and describes an improvement overapplication, Ser. No. 465,080, filed June 18, 1965.

More particularly the present invention relates to an apparatus formanufacturing yarns from continuous filaments which simulate yarnsderived from staple fibres.

The term continuous filaments as used herein refers to filaments whichare of an indefinite length and which in the practise of this inventionare continuously supplied by extrusion from a source of polymericmaterial.

In said application, Ser. No. 465,080 there is described and claimed,inter alia, apparatus for manufacturing yarns which comprises means forextruding a polymeric material into one or more continuous filaments, atraverse mechanism located some distance away from the extrusion meansand arranged to impart a reciprocating movement to the filament orfilaments, a body arranged to rotate with a peripheral speedsufficiently high to apply tension to the filament(s) and to assemblethe filament(s) around its surface in the form of a sleeve, means forwithdrawing the sleeve from the surface of the body at a slower speedthan the peripheral speed thereof, means for everting the sleevesimultaneously with, or subsequently to, its withdrawal from thesurface, and means for collecting the yarn so formed. The applicationfurther describes a convenient form of the apparatus whereby the yarnsleeve may be simply and successfully everted. This comprises arotatable body which contains an axially-extending passage and thesleeve is everted by pulling it therethrough in a direction opposite tothe direction of forward movement of the sleeve as it moves along thesurface of the rotatable body during its withdrawal. In the sameapparatus, the means which operate on the sleeve to withdraw it from thesurface of the body may serve to pull it through the axially-extendingpassage and may further serve to collect the yarn that is formed.

The practise of the above invention and the use of the apparatusdisclosed and claimed by the aforementioned specification provide meansfor the manufacture of a variety of continuous filament yarns and it isthe addition to this variety, of continuous filament yarns with superiorproperties, with which the present invention is concerned.

For any given arrangement of operating conditions the final properties,behaviour, appearance and structure of the continuous filament yarn inquestion will vary according to the chemical and physicalcharacteristics of the ice continuous filaments used in its production,while at the same time different operating conditions in the case of anyone type of continuous filaments will likewise give rise to anassortment of yarns.

Although the aforementioned invention possesses sufficient flexibilityof operation to meet the demands for yarns possessing differentproperties, the precise control of these properties over extendedperiods of time is often difficult and consequently it has been founddesirable to modify the apparatus described above so as to meet theprecise and accurate control of yarn properties that is often necessary.

Obviously, any further understanding of the mechanism of theaforementioned invention could well enhance its versatility and it isfrom an examination of the fundamentals of this invention that thepresent invention has been made. Extensive investigation of theoperation of the invention and the manner by which final yarn propertiesmay be influenced has led to a new appreciation of the rotatable body orgodet around which the yarn sleeve is assembled before its withdrawal.The profile and surface characteristics of the godet used seriouslyaffect the manner in which the yarn sleeve is laid and built and inturn, therefore, determines to a substantial extent the properties ofthe yarn that is finally produced. Variation in profile and surfacealone may be sufficient to determine the final use to which the yarn maybe put.

Thus, the structure and formation of the sleeve that forms on therotatable body depends significantly upon:

(a) the actual shape or profile of the body and, (b) the nature of thesurface upon which the yarn is laid and the sleeve later built.

Although the rotating body may have a variety of shapes, it is preferredthat it should be profiled so that there is an overall taper in thedirection in which the sleeve is moved therefrom, for this facilitatesthe withdrawal of the sleeve as a coherent, integrated structure whichis important in conveying to the yarn some of its characteristicfeatures and properties.

Among the diversiform rotating bodies that have been found to influenceyarn properties are those whose crosssectional shape, when viewed in adirection substantially coincident with their axes of rotation, may bedescribed generally (no sharply defined edges i.e. with rounded apices)as triangular, square, rectangular, rhomboidal, parallelepipedal,trapeziumoidal, trapezoidal, pentagonal and like regular sided figures,circular or elliptical. Such bodies may possess an essentially conical,hemispherical, parabolic, hyperbolic or logarithmic cross-section whenviewed in a direction substantially at right angles to their axes ofrotation. Also, any figure may be truncated so as to either increase ordecrease the minimum distance between its axis of rotation andcircumference,

Although it is preferred that any such figure should possess an overalltaper from one end to the other, the gradient of the slope may vary overthe taper and may even be reversed in places.

As well as effecting useful control over the final structure andproperties of the continuous filament yarns by changing the shape of therotatable body, changes in the nature of the external surface upon whichthe yarn sleeve is built will similarly influence yarn structure andproperties.

In this respect the nature of the surface may first be varied byemploying different materials for its construction such as metals,plastics or ceramics which in turn may be surface modified so that theyvery from smooth and continuous to rough and discontinuous, depending onthe type of filament or yarn that is used and the requisite yarnstructure. Surface roughness may take the form of slight indentations,scratches, whorls, ridges,

projecting teeth or hooks or other protrusions which may run either atrandom or in a pattern, or more substantial irregularities such as deepcuts, troughs, rifts or surface projections such as might form anodulated surface which likewise may occur at random or in a patternover the surface of the godet.

Such surface effects may or may not follow the general profile of therotatable body in depth or height.

Thus, the present invention provides an improvement in or modificationof the apparatus described in said application, Ser. No. 465,080 whereinthe body that is arranged to rotate with a peripheral speed sufficientlyhigh to apply tension to the fi1ament(s) and to assemble the filament(s)around its surface in the form of a sleeve possesses a discontinuous orirregular surface structure.

All surface irregularities may cover either in part or whole the surfaceof the rotatable body that receives the filament(s) via the traversingguide or plays some part in the formation and/or build of the yarnsleeve before it is pulled clear.

A preferred embodiment with respect to the rotatable body takes the formof a conical shaped body whose external surface is broken by an echelonstructure which may extend either partly or wholly from the apex to thebase of the body.

The combination of different godet shapes and surfaces thus provides avirtually infinite diversity of devices suitable for effecting an equalnumber of different yarn structures.

Particularly useful are those combination which affect yarn structure soas to advantageously influence such properties as air drag factor, bulkfactor, denier regularity and yarn pull-off tension, and given below areexamples that illustrate the mode of operation of the present inventionwhen employing a modified rotatable body. Air drag factor and bulkfactor may be found suitably defined in said patent application Ser. No.465,080.

These examples are of course in no way intended to limit the scope ofthe invention described herein.

Example 1 Referring to the accompanying drawing, two filaments 2, ofpolyhexamethylene adipamide from a spinneret 1 were passed through thefilament guide in the sinusoidal traverse mechanism 3 of a peak to peakamplitude of one and a half inches and a frequency of fifty cycles persecond and wound onto a conical shaped godet 7. The external surface ofthe godet was broken to give a ridged steplike or echelon profile whichextended at an oblique angle to its axis of rotation from the vicinityof the apex of the cone over approximately a A of its external curvedsurface area. The godet was positioned two feet below the spinneret faceand revolved at a rate of 18,000 rpm. The filaments were wrapped aroundthe godet in the form of a lissajou structure which was made up of twoserially connected helices, laid in opposite directions over a length ofone and a half inches of the godet surface with one overlapping theother. Each helix was formed during three rotations of the godet so thatsix turns were laid during the complete traverse cycle. The diameter ofthe resulting tapered tubular sleeve 4 was 2.5 inches at its widest partand 1.4 inches at its narrowest.

Although the instantaneous winding speed of the godet varied as thefilaments traversed the one and a half inches along its length in thedirection from the skirt to the nose, it was found that the denier andbirefringence of the filaments so traversed was substantially constantat all points along the laid length as shown in the table below.

The results also show that the filaments wound on the godet wereadequately oriented.

Under the action of the winding-up means the sleeve was continuouslypulled along the longtiudinal axis of the godet, slipped off the nosewhen it collapsed into an assemblage of loops 5, which was turnedinside-out and its direction of movement reversed by withdrawal throughthe stationary tube 9 located in the passage 6 and hollow shaft 8. Thestrand of loops was twisted into a yarn 10, in which form it waswound-up into a cheese at a rate of feet per minute.

The stationary tube device is similar to that disclosed and claimed inco-pending cognate patent application Nos. 52,331/ 65 and 52,332/ 65 andfunctions to advantageously influence the yarn bundle in a similarmanner to that indicated in the said co-pending cognate applications.When such a device is used, it is often found desirable, depending uponthe shape of the rotatable body, to widen the entrance to theaxially-extending passage so as to facilitate the passage of the yarnsleeve from the external surface of the body to the mouth of the tube.Thus, in some instances the apex of the rotatable body may take the formof a lip which protrudes from and encircles the mouth of the stationarytube.

It was observed that the sleeve could be pulled off the godet withoutassistance of mechanical means other than the wind-up.

The yarn which possessed 11.5 turns per inch had the followingproperties:

Denier 206 Extensibility percent 30 Yarn pull off tension gms 55 Airdrag factor 24.2 Bulk factor 3.5 Denier regularity (percentage meandeviation) perccnt 14 The last property was measured on a Fielden WalkerYarn Irregularity Tester. Individual filaments in the yarn were presentas loops which had limbs varying in length up to 18 inches, abirefringence of 0.036 (measured after 24 hours exposure to a normalatmosphere) and a denier of 1.4.

Example 2 Seven filaments of polyethylene terephthalate were fed asdescribed in example one, to a conical shaped godet possessing asymmetrical essentially extended S-shaped profile with a toothed surfacesimilar to that of a rasp file. The teeth projected about mm. above thesurface of the godet and there were roughly 28 teeth to every squarecentimetre of surface. The godet was positioned as in the previousexample and revolved at a rate of 15,000 rpm.

The filaments fed to the rotating godet built a similar lissajoustructure to that described above and since the overall profile of thegodet was similar in dimensions to that used in example one, thedimensions of the resultant tapered tubular sleeve were approximatelythe same too.

Also as in example one, the denier and birefringence of the traversedfilaments remained substantially constant over the laid length, and fora mean godet diameter of 1.9 inches and a mean winding-on speed of 7,450feet per minute the denier was 0.95 per filament and birefringence0.117.

Under the action of the winding-up means, the sleeve was pulled from thegodet, everted and withdrawn through a stationary tube device. Thestrand of loops was twisted into a yarn and in this form it was wound-upinto a cheese at a rate of 82.5 feet per minute.

Removal of the sleeve from the godet was achieved solely by the wind-upmeans.

The yarn which possessed 15 turns per inch had the following properties:

Denier 532 Extensibility percent 56 Air drag factor 15.2 Bulk factor1.38 Tenacity gms. per denier 1.1 Denier regularity (percentage meandeviation) percent 28 The last property was measured as indicated in theprevious example.

The use of such modified rotatable bodies and their influence on theresulting yarn was reflected in the attractive, regular and leanappearance and soft warm handle possessed by the yarns.

The yarns, which had the appearance of a twisted cotton yarn possessedgood covering power, could be readily dyed and fabrics made therefromhad a pleasant handle. Furthermore, they had excellent bulk and loftcharacteristics. In terms of structure the yarns comprised an assemblyof endless loops of varying lengths twisted together.

Although the examples describe the formation of yarns comprisingcontinuous filaments of circular cross-section, the invention mayreadily be applied to those of noncircular cross-section and thosederived from the slitting of film.

Continuous wholly or partly synthetic filaments which may be used inaccordance with this invention include those derived from polyamides(for example, polyhexamethylene adipamide, polyepsilon caprolactam andpolyhexamethylene sebacamide and copolymers of these or otherpolyamides), polyesters (for example, polyethyene terephthalate andpolyethylene isophthalate and copolymers of these or other polyesters),polyurethans, arcrylonitrile polymers (for example copolymers ofacronitrile, especially with other ethylenically unsaturated monomerssuch as vinyl chloride, vinyl acetate, methyl acrylate and vinylpyridine), vinyl polymers generally (for example, polyvinyl acetate,polyvinyl chloride and polystyrene), polymerised fluoroolefins (forexample, 'polytetrafiuoroethylene), polymerised hydrocarbons (forexample, polyethylene, polypropylene) and halogenated derivativesthereof, viscose rayon, cellulose acetate or similar derivatives ofcellulose and proteinaceous polymers.

Composite filaments and physical mixtures or blends of distinct polymerspecies may also be employed with success.

The yarn produced may be further stretched to increase the molecularorientation of its constituent filament or filaments and consequentlythe orientation process of the yarn according to this invention may becompleted in this Way if the filament or filaments are insufficientlyoriented before being wrapped around the rotating body. Furtherstretching may thus improve the regularity of the yarn with respect tosuch properties as extensibility, tenacity and denier.

The yarn as passed from the rotating body may be passed through a hotair vortex or steam chamber before being wound up. This ancillaryprocess will cause the material to crystallise and set and thus mayimprove the stability of the final yarn package. Further, any loopswhich project beyond the main part of the yarn structure will be causedto adhere to this main part. Such stray loops are a possible source ofsnagging and breakages when the yarn is used in a subsequent process, orproduces fabrics having an undesirable appearance. A1-

ternatively, the loops can be removed by a singeing treatment and thismay be applied to either the yarn or to the fabric produced therefrom.Although singeing to improve regularity or appearance can be achieved bynumerous techniques such as bringing the yarn or fabric into thevicinity of a red hot wire, it is preferred to contact the material withsuper heated steam. Singeing by this latter method is particularlysuitable if the yarn is to be Warp knitted.

The various post-treatments described above may be performed separatelyor in combination depending upon the requirements of the particularprocess, or they may either in part or whole be incorporated into acontinuous process so that yarn leaving the godet may be stretched, wetsteamed and singed in a continuous operation. If necessary, a spinfinish may be applied to the yarn follow ing the final treatment andprior to the winding of a yarn package.

I claim:

1. Apparatus for making a continuous filament yarn which comprises incombination means for extruding a polymeric material into at least onecontinuous filament, a traverse mechanism arranged to impart areciprocating movement to the filament, a body having a discontinuous orirregular surface structure and arranged to rotate with a peripheralspeed sufiiciently high to apply tension to the filament and to wind thefilament around its surface in the form of a sleeve, and means forwithdrawing the sleeve from the surface of the body in a directionessentially parallel to its axis of rotation and at a speed less thanthe peripheral speed of the body so as to insert twist, everting thesleeve simultaneously with, or subsequently to, its withdrawal from thesurface, and collecting the yarn that is formed.

2. Apparatus for making a continuous filament yarn as claimed in claim 1wherein the body contains an axiallyextending passage.

3. Apparatus for making a continuous filament yarn as claimed in claim 1wherein the surface structure of the body is in part both continuous anddiscontinuous.

4. Apparatus for making a continuous filament yarn as claimed in claim 1wherein the body possesses an overall taper from one end to the other.

5. Apparatus for making a continuous filament yarn as claimed in claim 4wherein the gradient of the taper varies between the ends of the body.

6. Apparatus for making a continuous filament yarn which comprises meansfor extruding a polymeric material into at least one continuousfilament, a traverse mechanism arranged to impart a reciprocatingmovement to the filament, a body having a discontinuous or irregularsurface structure and containing an axially-extending passage, said bodybeing arranged to rotate with a peripheral speed sufiiciently high toapply tension to the filament and to wind the filament around itssurface in the form of a sleeve, and means for Withdrawing the sleevefrom the surface of the body at a slower speed than the peripheral speedthereof, pulling the withdrawn sleeve through the passage in the bodythereby everting the sleeve and collecting the yarn that is formed.

References Cited UNITED STATES PATENTS 3,388,545 6/1968 Cannon et a1.57--l40 JOHN PETRAKES, Primary Examiner U.S. Cl. X.R. 57-34, 157.

